In an industrial vehicle such as a wheel loader, for example, when performing a work of loading sand, gravel, dirt, and the like into a dump truck, the vehicle is decelerated by pressing the brake pedal when approaching the dump truck and at the same time a working machine device (bucket) is lifted up by pressing the accelerator pedal, thereby maintaining the number of rotations of the engine at a high speed. Then, there is known a clutch cut off device that detects brake fluid pressure and a brake operation amount and, if the detected brake fluid pressure and the brake operation amount exceed a predetermined value, releases a forward/reverse clutch so as to cut off transmission of driving force (refer to Patent Literature 1).